1. Field of the Invention
The described invention relates to the field of opto-electronic circuits. In particular, the invention relates to an opto-electronic circuit that is coupled to a package substrate via solder bump technology.
2. Description of Related Art
Optical circuits include, but are not limited to, light sources, detectors and/or waveguides that provide such functions as multiplexing, demultiplexing and/or switching. Planar lightwave circuits (PLCS) are optical circuits that are manufactured and operate in the plane of the circuit. PLC technology is advantageous because it can be used to form small-scale components, such as array waveguide grating (AWG) filters, optical add/drop (de)multiplexers, optical switches, monolithic, as well as hybrid opto-electronic integration devices. Such devices formed with optical fibers would typically be much larger. Further, PLC structures may be batch fabricated on a silicon wafer.
An opto-electronic device circuit combines both electrical and optical functions. One type of opto-electronic circuit is a thermo-optic switch (TOS) made of a Mach-Zehnder interferometer. In a TOS, an optical signal is switched by providing an electrical input, i.e., an electrical current, to heat a heating element adjacent to an optical waveguide made of material, such as silica-on-silicon, that is sensitive to temperature. Heating the temperature-sensitive optical waveguide changes the refractive index and controls the path length of the optical waveguide, which results in the optical signal switching its optical path in the TOS, as is well-known. Various types of thermo-optic switches have been commercialized, such as 1xc3x971, 1xc3x972, 2xc3x972, 4xc3x974, 8xc3x975 and 8-arrayed 2xc3x972 varieties.
An opto-electronic device, such as a thermo-optic switch is typically coupled to an external electrical power supply by wire bonding from the power supply to the heating element of the thermo-optic switch.